Inputs
Example Data Table
| Scenario | Unit | Main shape | Key inputs | Allowance | Net total | Gross total |
|---|---|---|---|---|---|---|
| Indoor arena with rectangular footprint | m | Rectangle | L=90, W=70, Concourse: none, Support: 40×25 | 10% | 7,300.0 m² | 8,030.0 m² |
| Round arena with circular concourse ring | m | Circle | D=85, Concourse annulus: Rout=60, Rin=45 | 12% | 10,622.5 m² | 11,897.2 m² |
| Event hall as ellipse footprint | ft | Ellipse | a=320, b=240, Concourse: none, Support: off | 8% | 60,318.6 ft² | 65,144.1 ft² |
Use the calculator above to reproduce these scenarios with exact outputs in both m² and ft².
Formula Used
- Rectangle: A = L × W
- Circle: A = π × (D/2)²
- Ellipse: A = π × (a/2) × (b/2)
- Regular polygon: A = (n × s²) / (4 × tan(π/n))
- Concourse annulus: A = π × (Rout² − Rin²)
- Rectangular ring: A = (Lout×Wout) − (Lin×Win)
- Gross area: Agross = Anet × (1 + allowance/100)
- Occupancy (optional): persons ≈ Agross / area-per-person
How to Use This Calculator
- Select your unit system and choose a main footprint shape.
- Enter the shape dimensions. Use the same unit for all lengths.
- Optionally enable a concourse ring and/or support zone.
- Enter an allowance percentage to estimate gross floor area.
- Optional: provide area per person for a rough occupancy estimate.
- Press Calculate. Download CSV/PDF from the results panel.
Arena Floor Area Planning Notes
1) Purpose of the floor area breakdown
Arena programming typically starts with a clear split between the main event footprint, public circulation, and back-of-house support. This calculator mirrors that workflow by combining a main shape area with optional concourse and support zones, then applying an allowance. Using a consistent structure improves early cost checks, layout comparisons, and scope control.
2) Choosing a geometry that matches the footprint
Rectangles suit many bowl layouts and multi-use halls. Circles and ellipses are useful when the seating bowl drives a curved perimeter. Regular polygons can approximate segmented shells during concept design. Select the closest geometry first, then refine with detailed CAD takeoffs later. When comparing options, keep the same event floor assumptions and only change one variable at a time. This makes it easier to explain why a concept grows, shrinks, or shifts between iterations.
3) Concourse ring data and quick checks
Concourse area is modeled as a ring: outer minus inner boundary. A practical check is to confirm the ring thickness is realistic for your layout. For example, a circular concourse with Rout=60 m and Rin=45 m represents a 15 m band. The computed ring area is then added to the net total.
4) Allowance factor and reporting
Early-stage plans often include an allowance to cover circulation inefficiencies, structural zones, minor offsets, and rounding for coordination. A common concept range is 8–15%, but the right value depends on the level of detail and project standards. Gross area is calculated as net area multiplied by (1 + allowance/100).
5) Occupancy density and export outputs
If you enter “area per person,” the tool estimates occupancy as gross area divided by that density, producing a quick order-of-magnitude value. Use it for scenario comparison, not code approval. Export the CSV for traceable inputs and results, or the PDF for sharing in reviews and submittals.
FAQs
1) What does “net total” include?
Net total is the sum of the main footprint plus any enabled concourse and support areas, before adding the allowance percentage.
2) Why is there a gross area option?
Gross area helps early estimating by applying an allowance to net area, covering typical inefficiencies and small unmodeled spaces during concept development.
3) Can I model an irregular arena outline?
For irregular shapes, approximate using the closest geometry or a regular polygon, then confirm final areas using detailed drawings and measured takeoffs.
4) What units should I enter?
Use one consistent unit set: meters for metric or feet for imperial. The calculator converts and reports results in both square meters and square feet.
5) How do I set concourse dimensions correctly?
Outer dimensions must be larger than inner dimensions. For ring bands, the difference represents the concourse thickness around the arena footprint.
6) Is the occupancy estimate code-compliant?
No. It is a simple area-based estimate for comparison. Always verify occupant loads using the governing building code and the project’s life-safety strategy.
7) What is included in the downloads?
CSV and PDF exports include key inputs and computed results with timestamps, supporting transparent reviews, sharing, and quick re-checking later.